Report: Baltimore's air cleaner, but still among most polluted

Baltimore's air is healthier to breathe than it used to be, but the region still has some of the nation's worst smog and soot pollution, according to the American Lung Association.

In its annual report on the state of the nation's air, the advocacy group says the greater Baltimore-Washington region had nearly 41 fewer days of high ozone levels during 2010, the most recent year for which verified federal air-quality data are available. But the region still had the 13th most bad smog days out of 277 metropolitan areas across the country.

The Balt-Wash region also ranked 22nd worst for short-term particle pollution, based on the number of days with unhealthy levels of fine particles or "soot" measured in the air over a 24-hour period. That represented a modest improvement since 1996, according to the report. The region's chronic, year-round particle pollution is rated 56th highest among all the metro areas.

Nationwide, the lung association says its analysis found that in America’s most polluted cities, air quality was at its cleanest since the organization began making annual reports 13 years ago. The group credits regulations imposed under the federal Clean Air Act for reducing pollution from major sources such as coal-fired power plants, diesel engines, and SUVs.

"But despite these improvements," Lung Association President Charles D. Conner said in a statement, "America’s air quality standards are woefully outdated, and unhealthy levels of air pollution still exist across the nation, putting the health of millions of Americans at stake.”

The lung association's report lands amid a fierce political debate over air pollution standards adopted recently by the Environmental Protection Agency. Affected industries and their supporters have taken their complaints to court and Congress, arguing that the rules are unnecessarily strict, costly to implement and harmful to the economy. Power plant operators, for instance, have warned they'll shut some facilities down rather than comply.

But the Washington-based group says more than 127 million Americans - more than 40 percent of the population - still live in places with dangerous levels of either ozone or particle pollution, which can cause wheezing and coughing, asthma attacks, heart attacks, and even premature death.

Baltimore's summertime air has greatly improved since the 1990s, when the city and surrounding suburbs ranked among the smoggiest in the nation, trailing only Los Angeles and New York. In this latest report, it's no longer in the top 10 with the worst ozone pollution.

But based on the number of high-ozone days reported in 2010, the lung association gave failing grades on air quality to the counties in the greater Baltimore-Washington area, with Baltimore city receiving a better 'C' grade. On particle pollution, however, the situation was reversed, with the city's air graded failing and the suburbs better. For more on Maryland's air, go here.

While smog is a more widespread problem, particle pollution is considered more serious. Nearly 50 million Americans live in counties or cities with too many unhealthy spikes in particle pollution levels, the lung association said, while nearly six million people live in areas with unhealthy year-round levels of soot. Particle pollution is a mix of microscopic bits of ash, soot, diesel exhaust, chemicals, metals and aerosols, which can aggravate breathing problems, causing heart attacks and strokes.